On the verge of buying adult diapers?

I'm 15 and my period is sooooooooo heavy. If I don't wear a tampon (with a pad) to bed at night I'll wake up on the japanese flag. Last night I put in a tampon (regular) and went to bed thinking I was only going to sleep 8 hours, well I slept for over 12. I woke up and my entire 'lady system' hurt like hell. I was doubled over in pain as I rushed to the bathroom to remove the tampon. I thought I had TSS but there was no fever and it started improving an hour after I took the tampon out. If I don't wear a tampon to bed the moment I stand up in the morning blood starts pouring down my legs. At night I plaster the insides of my underwear with like 4 pads (like on the back and stuff). This is so ridiculously not fun to deal with and I'm seriously just on the verge of buying adult diapers for night time. Is there any other way other than BC that I can contain it?